Trying new sexual things

so one of my really good guy friends who I've been sleeping with for the past 6 months has given me a proposition of trying something new in bed. we are really good friends and he is bisexual there are NO feelings in between its a really long story lol but anyways he asked me how I would feel about adding another guy. he's told me about how much he thinks I'd enjoy getting double penetrated! I'm not a virgin from behind so I feel it would be something surreal has anyone tried it or had a 3 some! I hope to get responses I wrote anonymously but hope I still get feedback